dbis_core/docs/adr/0005-settlement-architecture.md

ADR-0005: Multi-Layer Settlement Architecture

Status

Accepted

Context

The DBIS system requires settlement across multiple dimensions:

• Multiple sovereign banks (33 SCBs)
• Multiple asset types (fiat, CBDC, commodities, securities)
• Multiple settlement modes (RTGS, atomic, T+1)
• Cross-chain operations
• Real-time and batch processing

Decision

Implement a multi-layer settlement architecture:

1. Instant Settlement Network (ISN): Real-time atomic settlement
2. Global Settlement System (GSS): Four-layer architecture (Sovereign, DBIS Master, Smart Clearing, Finality)
3. Global Atomic Settlements (GAS) Network: Multi-dimensional atomic settlement
4. Omega-Layer: Final settlement layer for reality-spanning coherence
5. Cross-Chain Settlement: Atomic swaps across different chains

Consequences

Positive

• Supports multiple settlement modes
• Atomic settlement guarantees
• Cross-asset settlement capability
• Scalable architecture
• Finality and irreversibility

Negative

• Complex architecture
• Multiple systems to maintain
• Potential for coordination overhead

Risks

• Settlement failures across layers
• Performance at scale
• Complexity in debugging

Alternatives Considered

1. Single Settlement Layer: One settlement system

   • Pros: Simple
   • Cons: Cannot handle all requirements

2. Multi-Layer Architecture: Chosen approach

   • Pros: Flexible, comprehensive, supports all use cases
   • Cons: More complex

Implementation

• ISN: src/core/settlement/isn/
• GSS: src/core/settlement/gss/
• GAS: src/core/settlement/gas/
• Cross-Chain: src/core/settlement/cross-chain/

References

• ISO 20022 Settlement Standards
• Real-Time Gross Settlement (RTGS) Systems